Further characterization of the binding properties of a GalNAc specific lectin from Codium fragile subspecies tomentosoides.
Previous study on the binding properties of a lectin isolated from Codium fragile subspecies tomentosoides (CFT) indicates that this lectin recognizes the GalNAc alpha1--> sequence at both reducing and nonreducing ends. In this study, the carbohydrate specificity of CFT was further characterized by quantitative precipitin (QPA) and inhibition of lectin-enzyme binding assays. Of the glycoforms tested for QPA, all asialo-GalNAc alpha1--> containing glycoproteins reacted well with the lectin. Asialo hamster and ovine submandibular glycoproteins, which contain almost exclusively Tn (GalNAc alpha1-->Ser/Thr) residues as carbohydrate side chains, and Streptococcus type C polysaccharide completely precipitated the lectin added, while the GalNAc beta1-->containing Tamm-Horsfall Sd(a+) glycoprotein and its asialo product were inactive. Among the oligosaccharides tested for inhibiting lectin-glycoprotein interaction, GalNAc alpha1-->3GalNAc beta1-->3Gal alpha1-->4Gal beta1--> 4Glc(Fp) and Gal beta1-->3GalNAc alpha1-->benzyl (T alpha) were the best, and about 125-fold more active than GalNAc. They were about 3.3, 6.6, and 43 times more active than Tn containing glycopeptides, GalNAc alpha1-->3(LFuc alpha1--> 2)Gal(Ah) and Gal beta1-->3GalNAc(T), respectively. From the present and previous results, it is concluded that the combining site of CFT is probably of a groove type that recognizes from GalNAc alpha1--> to pentasaccharide(Fp). The carbohydrate specificity of this lectin can be constructed and summarized in decreasing order by lectin determinants as follows: Fp and T alpha > Tn cluster > Ah >> I/II.
Wu
A M
AM
Glyco-Immunochemistry Research Lab., Institute of Molecular and Cellular Biology, Tao-yuan, Taiwan.
Song
S C
SC
Chang
S C
SC
Wu
J H
JH
Chang
K S
KS
Kabat
E A
EA
D000116:Acetylgalactosamine / Q000378:metabolism*; D000818:Animals; D001212:Asialoglycoproteins / Q000378:metabolism; D002240:Carbohydrate Sequence; D011232:Chemical Precipitation; D000460:Chlorophyta / Q000737:chemistry*; D006224:Cricetinae; D037102:Lectins / Q000378:metabolism*; D008969:Molecular Sequence Data; D009088:Mucoproteins / Q000378:metabolism; D009844:Oligosaccharides / Q000494:pharmacology; D009961:Orosomucoid / Q000031:analogs & derivatives / Q000378:metabolism; D011135:Polysaccharides, Bacterial / Q000378:metabolism; D012756:Sheep; D013291:Streptococcus / Q000737:chemistry; D013363:Submandibular Gland / Q000737:chemistry; D058949:Uromodulin
D001212:Asialoglycoproteins; D037102:Lectins; D009088:Mucoproteins; D009844:Oligosaccharides; D009961:Orosomucoid; D011135:Polysaccharides, Bacterial; D058949:Uromodulin; C017030:asialoorosomucoid; C027158:polysaccharide C-substance (Streptococcus); D000116:Acetylgalactosamine